Considering the CpG-ODN species specificity and to the lack of TLR9 expression on IGROV1 cells, the effect cannot be mediated by a direct interaction between the oligonucleotide and tumor cells, instead it is likely that peritumoral TLR9-expressing cells, such as innate immune cells and/or endothelial cells, fibroblasts and epithelial cells, directly respond to CpG-ODN and down-regulate DNA repair in tumor cells through a direct cell-cell interaction and/or by secreting soluble factors. The gene discussed is TLR9; the disease is neoplasm.